NEW YORK, April 14 (Reuters) - U.S. stock index futures edged higher on Monday, following a large selloff last session, with earnings results from Citigroup lifting sentiment while traders kept tabs on the possible escalation of hostilities in Ukraine.

* Citi shares rose 3 percent in premarket trading, after the bank said its quarterly net profit rose as a smaller loss on its troubled assets made up for a drop in revenue and profit from its core trading and lending businesses.

* On Friday, JPMorgan’s disappointing earnings were partly to blame for the day’s selloff. Biotech and other momentum stocks led the Nasdaq Composite lower, pushing the index below 4,000 for the first time in two months.

* Ukraine’s acting president threatened military action on Monday, after pro-Russian separatists occupying government buildings in the east ignored an ultimatum to leave and another group of rebels attacked a police headquarters.

* Russian stocks and the rouble fell sharply as Ukraine’s preparedness to fight the rebels heightened fears of Russian military intervention and more western sanctions against Moscow.

* S&P 500 e-mini futures rose 6.75 points, while fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract, pointed to a slightly higher open. Dow Jones industrial average futures were up 45 points and Nasdaq 100 futures rose 14 points.

* Medtronic shares fell 4.6 percent in premarket trading after a court ruling that would prevent the company from selling its CoreValve system in the United States because of a patent infringement. Shares of Edwards Lifesciences, on the other side of the ruling, rallied 12.5 percent.

* Lexicon Pharmaceuticals rallied 24 percent premarket after it said its experimental drug to treat diabetes met a main goal in a mid-stage study on patients with type 1 diabetes. (Reporting by Rodrigo Campos; Editing by Chizu Nomiyama)